AP BIOLOGY

Detailed explanation-1: -If a person has an error in a DNA repair gene, mistakes remain uncorrected. Then, the mistakes become mutations. These mutations may eventually lead to cancer, particularly mutations in tumor suppressor genes or oncogenes. Mutations in DNA repair genes may be inherited or acquired.

Detailed explanation-2: -Genetic mutations can change how proteins function. Some types of genetic mutations change proteins in ways that cause healthy cells to become cancerous.

Detailed explanation-3: -Cancer is caused by changes to DNA. Most cancer-causing DNA changes occur in sections of DNA called genes. These changes are also called genetic changes. A DNA change can cause genes involved in normal cell growth to become oncogenes.

Detailed explanation-4: -Cancer initiates from high genome modifications or DNA aberrations such as deletions, translocations, loss of heterozygosity and amplifications. DNA damage and defects in the repair genes are responsible for the accumulation of mutations and cancers [66].

Detailed explanation-5: -In 1970, the oncogene of Rous sarcoma virus, SRC (for sarcoma, and pronounced “sark, ” denoting the type of connective tissue cancer it causes), was identified and shown to be the first clear example of a gene that can transform a cell from normal to perpetual cancerous growth.